I can say that this is not correct with my friend's AT&T iPhone 5. We are in Dallas (in McKinney, a suburb) and just last week we turned off his wifi, ran a speed test, and it reported 22mb d/l and 10mb u/l. There is nothing special about his phone - not unlocked, nor has he done anything to it to remove the limits. I was testing out the 4G LTE speed on his to see if it was worth it to upgrade from my iPhone 4S. My 4S' speed was only 5.5mb d/l and 1.5mb u/l.